1. Field of Invention
The present invention relates to a gate driving circuit and a driving circuit unit thereof. More particularly, the present invention relates to a gate driving circuit and a driving circuit unit thereof in a liquid crystal display.
2. Description of Related Art
In a conventional liquid crystal display, there is always an external gate driver used to drive scan lines of the liquid crystal display. However, the production cost is expensive when using the external gate driver. Therefore, lowering the production cost for the gate driver is very important.
In the prior art, a gate driving circuit fabricated on a glass substrate is used to output the gate driving signals to the scan lines, so as to replace the external gate driver used before and lower the production cost. FIG. 1 shows a conventional gate driving circuit. The gate driving circuit 100 includes driving circuit units 102, controlled with a power voltage VSS and clock signals CK and XCK which have opposite phases thereof, for sequentially outputting driving signals SN1 . . . SNN to the corresponding scan lines. However, when producing a large liquid crystal display, the loads of the scan lines increase accordingly. Therefore, due to the increasing loads, the driving signals would be distorted, so that the corresponding scan lines cannot be operated properly. Besides, transistors in the gate driving circuit also have to become relatively bigger, so as to output enough current to drive the scan lines, and the heat effect in the circuit is therefore more serious.
For the foregoing reasons, a gate driving circuit capable of improving the outputted driving signals and preventing the circuit from the heat effect problem is needed.